Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Hitachi Cable, Inc.

Yuzuru Hosoe

Kiwamu Tanahashi

Tomoo Yamamoto

Ichiro Tamai

Akira Ishikawa

Tetsuya Kanbe

Yoshibumi Matsuda

Yotsuo Yahisa

Yoshio Takahashi

Masaaki Futamoto

Nobuyuki Inaba

Yoshihiro Shiroishi

Akira Kato

Masukazu Igarashi

Koji Sakamoto

Ikuko Takekuma

Kazusuke Yamanaka

Atsushi Kikugawa

Yoshiyuki Hirayama

Shinji Narishige

Satoshi Matsunuma

Naoto Endo

Norio Ohta

Yutaka Sugita

Yukio Honda

Noboru Shimizu

Hiroyuki Nakagawa

Kenji Furusawa

Mitsuhiro Shoda

Yasutaro Uesaka

Hiroyuki Kataoka

Akira Osaki

Emi Mangyo

Hiroyuki Suzuki

Fumiyoshi Kirino

Yoshiki Kato

Hiroaki Nemoto

Reiko Arai

Toshinori Ono

Nagatugu Koiso

Keikichi Ando

Shinji Fukaya

Jun Fumioka

Yoko Ogawa

Kazuhiro Ura

Yoshifumi Matsuda

Hiroshi Ikeda

Kazuetsu Yoshida

Masatoshi Takeshita

Masaki Ohura

Noriyoshi Goda

Tomio Iwasaki

Yukio Katoh

Hiroyuki Matsumoto

Hiroyoshi Matsumura

Keikichi Andoo

Masahiro Kitada

Ryoichi Nakatani

Yoshinori Honda

Naoki Kodama

Katsumi Mabuchi

Hiroshi Tani

Tsuneo Suganuma

Futoshi Tomiyama

Takayuki Ichihara

Katsuo Abe

Kazuyuki Nagatsuma

Joe Inagaki

Fumihiko Ishida

Takao Yonekawa

Susumu Funamoto

Enji Fujita

A medium having high medium S/N and excellent corrosion resistance is achieved. In one embodiment, an adhesion layer, a soft magnetic layer, an intermediate layer, a magnetic recording layer, and a protective layer are deposited, in order, on a substrate. The soft magnetic underlayer consists at least of two soft magnetic layers, the first soft magnetic layer formed on the recording layer side being composed of an amorphous alloy containing 85 at. % or less of Co, and the second soft magnetic layer formed on the substrate side being composed of an alloy containing more than 85 at. % of Co.

Perpendicular magnetic recording medium with high medium S/N

Embodiments of the invention ensure that a perpendicular magnetic recording medium having a granular magnetic recording layer made of CoCrPt alloy and Si oxide provides both high SNR and thermal stability. In one embodiment, a substantially amorphous grain boundary layer of a magnetic recording layer made of CoCrPt alloy and Si oxide contains a ferromagnetic element in a concentration from about 30 at. % to 50 at. % or more preferably from about 35 at. % to 47 at. %, so that intergrain exchange interaction takes place moderately. As a consequence, SNR of 18 dB or more and thermal stability of 3%/decade or less are achieved.

Perpendicular magnetic recording medium having grain boundary layer containing ferromagnetic element

Embodiments of the embodiment are directed to reducing the inter-granular exchange coupling of an oxide granular medium and obtaining a high media S/N value, resulting in an areal recording density greater than 23 gigabits per square centimeter or more being achieved. In one embodiment, a magnetic recording medium comprises a structure laminating a soft-magnetic underlayer, a lower intermediate layer including Ru, an upper intermediate layer consisting of Ru crystal grains and oxide crystal grain boundaries, a magnetic recording layer consisting of crystal grains and oxide crystal grain boundaries, in order, on a substrate, growing crystal grains of the magnetic recording layer epitaxially on the Ru crystal grains of the upper intermediate layer, and growing the crystal grain boundaries of the magnetic recording layer on the crystal grain boundaries of the upper intermediate layer.

Perpendicular magnetic recording medium and manufacturing of the same

Embodiments of the invention provide a medium which provides high media S/N and good corrosion resistance. According to one embodiment, in a perpendicular magnetic recording medium at least comprising a soft-magnetic underlayer, a seed layer, an intermediate layer, a magnetic recording layer and an overcoat layer which are stacked over a substrate in order, the magnetic recording layer has a granular structure which consists of many columnar grains of CoCrPt alloy and a grain boundary layer containing an oxide, the seed layer is made of TaNi alloy or TaTi alloy and the intermediate layer is made of Ru or Ru alloy which contains about 80 at. % Ru or more.

Perpendicular magnetic recording medium for high density recording and manufacturing of the same

Embodiments of the invention provide a perpendicular magnetic recording medium that not only attains the magnetic isolation of crystal grains in a magnetic recording layer from one another in a region of the medium in which the thickness of an intermediate layer is equal to or smaller than about 20 nm but also exhibits excellent crystallographic texture and that exhibits small medium noise, excellent thermal stability, and high write-ability. In one embodiment, a perpendicular magnetic recording medium has at least a soft-magnetic underlayer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a magnetic recording layer successively formed on a substrate. The magnetic recording layer is composed of ferromagnetic crystal grains and oxides or nitrides, the third intermediate layer is composed of Ru or an Ru alloy, the second intermediate layer is composed of a metal or an alloy having the face-centered cubic lattice structure, and the first intermediate layer is composed of a metal or an alloy having the hexagonal close-packed structure.

Perpendicular magnetic recording media and magnetic storage apparatus using the same

Embodiments of the invention provide a perpendicular magnetic recording medium capable of reconciling a high recording density with high thermal stability, and having a high write-ability while maintaining high magnetic anisotropy energy. In one embodiment, a perpendicular magnetic recording medium has a soft-magnetic underlayer, and magnetic recording layers, and the magnetic recording layers comprises a first recording layer containing magnetic grains oriented in a direction normal to a medium plane, and a second recording layer containing magnetic grains tilted in a cross-track direction. There can be provided a perpendicular magnetic recording medium resistant to thermal fluctuation, small in medium noise, and excellent in write-ability.

Magnetic recording medium containing first and second recording layers, each layer containing a columnar structure

Embodiments of the invention are directed to a medium which provides high media S/N and good corrosion resistance. According to one embodiment, in a perpendicular magnetic recording medium at least comprising a soft-magnetic underlayer, a seed layer, an intermediate layer, a magnetic recording layer and an overcoat layer which are stacked over a substrate in order, the magnetic recording layer has a granular structure which includes many columnar grains of CoCrPt alloy and a grain boundary layer containing an oxide, the seed layer is made of TaNi alloy or TaTi alloy and the intermediate layer is made of Ru or Ru alloy which contains 80 at. % Ru or more.

Perpendicular magnetic recording medium for high density magnetic recording and manufacturing of the same

Embodiments in accordance with the present invention provide a perpendicular magnetic recording medium which is easy to record, offers superior thermal stability of recording magnetization, and allows high-density recording. In one embodiment, a perpendicular magnetic layer with controlled magnetic properties is used as a magnetic storage layer of a perpendicular magnetic recording medium, the magnetic properties having been controlled such that an indicator &#x3c3;h[%] of the dispersion of magnetization switching fields in the perpendicular magnetic layer and an indicator D[nm] of the intensity of exchange interactions, in film surface directions, in the perpendicular magnetic layer satisfy inequalities &#x3c3;h/27+D/90&#x3c;1, and D&#x3e;20. The indicators can be measured using a magnetometer.

Perpendicular magnetic recording medium, method of evaluating magnetic properties of the same

There is provided a perpendicular magnetic recording medium comprising a non-magnetic layer having a face-centered cubic structure, an antiferromagnetic layer provided on the non-magnetic layer, a soft magnetic underlayer provided on the antiferromagnetic layer, and a perpendicular recording layer provided on the soft magnetic underlayer, which magnetic recording medium makes it possible to realize a recording density not less than 50 Gb/inand makes the error rate thereof low while suppressing the spike noise.

Perpendicular magnetic recording media

A magnetic recording medium having a high coercive force and being capable of high-density writing/reading has a substrate, a soft magnetic layer, a non-magnetic intermediate layer, a magnetic layer, a protective layer, and a lubricating layer. The magnetic layer is characterized by stacking fault density and dispersion of particle diameters. The stacking fault density should preferably be no larger than 0.05, and the dispersion of particle diameters should preferably be no larger than 0.4. The magnetic recording medium has a coercive force larger than 4000 Oe, is highly stable to thermal decay, and has a recording density in excess of 50 Gbit/in.

Magnetic recording medium and its manufacturing method and magnetic recording system using such a magnetic recording medium

A magnetic recording medium having a substrate, an under-layer formed on the substrate, a magnetic layer formed on the substrate and a protective layer formed on the magnetic layer. The magnetic layer comprises Co, Cr and Pt with a thickness being from 10 nm to 22 nm. Further, a coercivity of the magnetic layer is not less than 2000 Oe, and a fluctuation field of magnetic viscosity at a field strength equal to remanence coercivity or coercivity is not less than 30 Oe.

Magnetic recording medium and magnetic recording and reproducing apparatus

Provided are a double-layer perpendicular magnetic recording medium having a high medium S/N at an areal recording density of 50 Gbits or more per square inch, and a magnetic storage apparatus having excellent reliability with a low error rate. The perpendicular magnetic recording medium is formed by sequentially laminating a domain control layer, an amorphous soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer on a substrate. The domain control layer is a triple-layer film formed by laminating a first polycrystalline soft magnetic layer, a disordered antiferromagnetic layer, and a second polycrystalline soft magnetic layer from a substrate side.

Perpendicular magnetic recording media, manufacturing process of the same, and magnetic storage apparatus using the same

A magnetic recording system includes an in-plane magnetic recording medium having a magnetic layer fabricated on a single underlayer or on a plurality of underlayers respectively fabricated on a substrate; a driver unit for driving the in-plane magnetic recording medium in a write direction; a magnetic head having a read unit and a write unit; a unit for moving the magnetic head relative to the in-plane magnetic recording medium; and a read/write signal processing unit for reading an output signal from the magnetic head and writing an input signal to the magnetic recording media, wherein the read unit of the magnetic head is a magnetoresistive head and the single underlayer or at least one of the plurality of underlayers is made of Co-containing amorphous material or fine crystal material, or is made of alloy material, the alloy material having as the main components at least one element selected from a group consisting of Cr, Mo, V and Ta and containing at least one element selected from a group consisting of B, C, P and Bi. The magnetic recording system can be realized which can read and write high density information and have high reliability.

Magnetic recording media and magnetic recording system using the same

In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, means for causing the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor means for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magnetoresistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of the underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as selected from the group consisting of Nb and Ta.

Magnetic recording media and magnetic storage apparatus using the same

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Hino, Japan

Yuzuru Hosoe